Add X509CertificateBytes which uses CRYPTO_BUFFER instead of macOS-native certificate types.

net/cert/x509_util_ios.cc

Index: net/cert/x509_util_ios.cc
diff --git a/net/cert/x509_util_ios.cc b/net/cert/x509_util_ios.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9bf41850efa7a0aee487c7a862cc959f11989211
--- /dev/null
+++ b/net/cert/x509_util_ios.cc
@@ -0,0 +1,22 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/cert/x509_util_ios.h"
+
+#include "net/cert/x509_certificate.h"
+
+namespace net {
+
+namespace x509_util {
+
+base::ScopedCFTypeRef<SecCertificateRef>
+CreateSecCertificateFromX509Certificate(const X509Certificate* cert) {
+  return base::ScopedCFTypeRef<SecCertificateRef>(
+      reinterpret_cast<SecCertificateRef>(
+          const_cast<void*>(CFRetain(cert->os_cert_handle()))));
+}
+
+}  // namespace x509_util
+
+}  // namespace net